What does double pumper on a carb mean?

The Double Pumper gets its name from the twin accelerator pump outlets (arrows) for both the primary and secondary throttle bores. This is an HP version carburetor where the choke housing is removed for smoother air inlet into the carburetor. ... The manual choke can easily be upgraded to electric control at a later date.

1. Do I need a double pumper carb?
2. How do I identify a Holley double pumper?
3. Is 600 cfm carb big enough?
4. How much horsepower will a 650 cfm carb support?
5. What's better mechanical secondaries or vacuum secondaries?
6. What is a high rise double pump carburetor?
7. Is the Holley Street Avenger a double pumper?
8. What is a pumper carb?

Do I need a double pumper carb?

Certainly if the engine has high compression, a serious cam, a single-plane intake, 3.70:1-or-steeper gears, and a manual trans or an automatic with a high-stall converter, you should definitely run a double-pumper. Ditto if you have a very lightweight (under-3,100 pounds) car regardless of the overall combo.

How do I identify a Holley double pumper?

It's like a "VIN" for your carburetor and should be hand-stamped on the front of the choke tower to the right of the vent tube on most typical Holley carbs. The list number typically is four to six digits long and may or may not have a suffix number behind it. The date code will be right below it.

Is 600 cfm carb big enough?

A 600-cfm carburetor may perform quite well on a stock 350 Chevy. However, the minute you start weaving in power adders like a hotter cam, a dual-plane performance intake manifold, and aluminum heads you're going to need 700-750 cfm.

How much horsepower will a 650 cfm carb support?

So, using your Google-Fu you type "How much power can a 650 cfm carb support?" Well, chances are that you'll get answers in the 450-470 hp range, but that's not really the right way to look at it. In fact, horsepower—or even torque, for that matter—doesn't matter at all.

What's better mechanical secondaries or vacuum secondaries?

In summary, mechanical-secondary carbs are much more sensitive to engine size, drivetrain gearing, vehicle weight, and rpm range compared with the controlled secondary configuration, which is why the double-pumpers are offered in many more cfm ratings than the vacuum-secondary carbs.

What is a high rise double pump carburetor?

Double pump carb - carb with two accelerator pumps. Provides extra squirt of fuel to spin up the engine faster without leaning out the mixture which can cause detonation, pinging and knocking. All of which are bad news in a high performance engine.

Is the Holley Street Avenger a double pumper?

BOWLING GREEN, Ky. – Holley Performance Products has announced the introduction of its all-new Ultra Street Avenger and Ultra Double Pumper carburetors, which have been designed for improved performance, weight savings and show quality looks.

What is a pumper carb?

A pumper carb uses an accelerator pump to force gasoline into the intake on opening the throttle. A non-pumper uses the vacuum signal/pressure differential of opening the slide. The squirt of gas gives you better response.